Where the cutter bar and sickle are long, in some arrangements, two sickle bar sections are provided which are reciprocated in opposite directions and operated with separate reciprocating drives.
In the U.S. Pat. No. 7,658,059 (Majkrzak) issued to Crary industries on Feb. 9, 2010 is disclosed a drive arrangement for split sickle bar sections which utilizes separate drives for each sickle bar and provides an arrangement for synchronizing the movement of the sickle bars so they each reach the end of the reciprocating path simultaneously. This is carried out by providing a single marker on the movement aligned with the end of the path so that, by detecting whether the markers are aligned, the speed of drive of the sickle bars can be relatively increased or decreased to try to maintain the alignment of the markers. This arrangement does not appear to have obtained any commercial success.